1. Field of the Invention
The present invention relates to an image pickup apparatus that has a continuous focusing function for performing continuous focusing actions, and an image pickup method used for the same.
2. Description of the Related Art
Various types of cameras having an auto-focus function have been known.
Japanese Patent Application Laid-Open No. 08-248510 discloses a hybrid camera having a still camera part, a video camera part, and a taking lens shared by the parts, wherein, in a still image taking mode, the camera performs servo control based on repetitive detection by a focus detection device when a motion detection device detects that a subject is moving and performs one-shot control that stops a lens drive to make focus lock in response to attainment of an in-focus state when the motion detection device detects that a subject is not moving.
Japanese Patent Application Laid-Open No. 2003-207712 discloses an imaging device that adjusts the focus of optical equipment, including: an optical part that generates a subject image by receiving a light beam from a subject; a contrast detection part that detects the contrast value of the subject image; a range finding part that computes distance information on the distance from a focusing unit to the subject; an adjustment indication reception part that receives indication information showing the adjustment of the focus of the optical part; a focus control part that adjusts the focus of the optical part when the adjustment indication reception part receives the indication information; and a distance information storage part that stores the contrast value that the contrast detection part detects and the distance information that the range finding part computes, when the adjustment indication reception part receives the indication information.
Japanese Patent No. 3934954 (Japanese Patent Application Laid-Open No. 2003-232984) discloses a CPU that, before performing a focusing action in response to focusing instruction operation, compares present image data obtained immediately after the focusing instruction operation and obtained when a focus lens is at a previous focusing position detected by a previous focusing action with a previous image data obtained in the midst of the previous focusing action or immediately after finishing the previous focusing action and obtained when the focus lens is at the previous focusing position, and judges whether or not the in-focus state from the previous focusing action is maintained. In the case of detecting the focusing position when the in-focus state is not maintained, the focus lens is not driven or the driving area of the focus lens is narrowed.